1. Field of the Invention
The invention relates to a system or assembly for installing a fastening unit such as a fastener. The assembly utilizes a housing, a drive mandrel and a mounting surface. The drive mandrel has a rotational axis and can be brought into engagement with the fastening unit or fastener through an opening in the mounting surface.
2. Discussion of Background Information
An assembly or placing device of this type can be used, for example, for installing or placing a fastening unit of the type disclosed in DE 102 53 888 B4, the disclosure of which is expressly incorporated by reference herein in its entirety. The fastening unit utilizes a blind rivet nut and a screw. The blind rivet nut has a rivet shank with an internal thread and a set head. Such a fastener can be used to fasten components to thin-walled workpieces, such as, e.g., metal sheets.
The fastening unit is installed by guided it first through the component to be fastened (e.g., via a opening in the component) and subsequently through a bore in the metal sheet. While the set head of the blind rivet nut is held in contact with the metal sheet, an axial tensile force is exerted on the rivet shank of the blind rivet nut via the screw. This leads to the formation of a closing head on the other side of the metal sheet, so that the blind rivet nut is attached in the metal sheet in the manner of a blind rivet. In order to prevent the blind rivet nut from being rotated with the screw during the installing or placing process, the blind rivet nut generally has a polygonal cross section in an area of the rivet shank (the opening in the workpiece being similarly embodied), so that torque introduced through the screw is absorbed by the workpiece.
The component to be fastened typically is already provisionally attached to the workpiece or metal sheet before the placement of the fastening unit or fastener. This provisional fastening is thus carried out, e.g., by way of plastic clips. The fastening unit or fastener must then be inserted through the component to be fastened and subsequently guided through the workpiece. However, it is often necessary to slightly move or rotate the component to be fastened in order to be able to guide the fastening unit through the opening in the workpiece. This occurs, in particular, when the rivet shank of the fastening unit has a polygonal cross section that must be brought into alignment with the corresponding shaped opening in the workpiece.
In order to provide for a quick and reliable placement of the fastening unit, it is thereby desirable to guide the fastening unit or fastener into the workpiece.